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APPENDIX A
PROGRAM OVERVIEW
GENERAL DESCRIPI ION
PAVDRN is a program package that was developed at The Pennsylvania State
Un~versity's Pennsylvania Transportation Institute. The work was sponsored by the National
Cooperative Highway Research Program Project I-29, "Improved Surface Drainage of
Pavements."
PAVDRN is intended for use by highway design engineers and determines the
likelihood of hydroplaning on various highway pavement sections. It does this by computing
the longest flow path length over a given pavement section and determining the water film
thickness (depth of water above the roughness asperities of the pavement surface) at points
along the path. The water film thickness is used to estimate the speed at which hv~ronIanin~
,`
~,
will occur. A worst-case scenario is examined by determining the water film thickness and
hydroplaning speeds along the longest flow path length under steady-state conditions with a
uniform rainfall rate. The predicted hydroplaning speed is compared to the design speed of the
facility established by the engineer. Results are printed in a summary report format.
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INSTALLATION
PAVDRN is distributed on two disks. The program runs under W~ndowsTM 3. fix or
higher. (A FORTRAN version of the program is also available.) At a minimum, the
computer used to run PAVDRN should have fiche following characteristics:
· 80386SX or DX processor or above
· MS-DOS 6.2 or above
.
WindowsTM 3. fix running ~ standard or enhanced mode or above
The following steps describe the installation process:
I. Insert distribution diskette ~ into a floppy disk drive.
2. From the W~ndowsw menu bar at the top of the screen, use the mouse and the left
hand mouse button to click on File.
3. From the File pull-down menu, click on Run.
4. In the dialog box for Run, type a:setup or b: setup (depending upon which floppy
drive you have Vertex distribution diskette ~ Anton.
5. Press Enter or click on OK.
6. Follow the directions shown on the Setup screens that follow. One of the first steps
will be to provide the drive and subdirectory In which you want fiche program files
installed. Certain files will also be copied to other subd~rectones like the
\WINDOWS\SYSTEM subdirectory In addition to the files copied to the directory
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you indicated for the program files. Only the most current versions of files will be
copied. This is intentional.
The installation process creates a program group In the Program Manager window
labeled PAVDRN. When the group is opened, three program icons are displayed. The one
that most users will use routinely is ache PAVDRN program whose icon is a ram cloud. The
PAVDRN program is started by double-clic~ng the left mouse button on this icon. The other
two programs, SHARE.EXE and GSW.EXE, are only needed if a message appears on the
user's screen prompting the user to start these programs. In most cases, they are not needed.
USING PAVDRN
After starting the PAVDRN program by double-clicking on the rain cloud icon labeled
PAVDRN ~ the PAVDRN program group, the user should see the first of three screens that
make up the user interface for the PAVDRN program. Screen ~ requires the user to input
general ir formation about the simulation. Detailed information on each of the data items
required for the first screen appears In the following. Screen 2 requires the user to input data
concerning the specific section with which he or she is working or designing. The third screen
is a screen used for displaying the data set constructed using Screens ~ and 2. It is also used to
display the output from the PAVDRN program, which includes information about water film
thickness and hydroplaning speeds along the length of the flow path.
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In general, the steps taken to use PAVDRN are:
I. Open the PAVDRN program group.
2. Double-click on the PAVDRN rain cloud icon.
3. Edit the values and text on Screen ~ for the current pavement section or simulation.
4. Go to Screen 2.
5. Edit the values on Screen 2 for the current pavement section or simulation.
6. Return to Screen I.
7. Click on File on the menu bar at the top of the screen.
8. Click on Save on the drop down File menu and enter the name of the file In which
you wish to save the data. (Another subdirectory can be selected at this point if
desired).
9. Select Run PAVDRN from the File drop down menu or the Analysis drop~own
menu on the menu bar at the top of the screen.
10. Select View PAVDRN results from the Analysis drop~own menu or the View
drop~own menu on the menu at the top of the screen.
. Print the output report or exit the viewing screen by clicking on one of the buttons
at the bottom of the viewing screen.
By using the View drop down menu, the output report or the data file can be examined
neither file can be edited using this screen. The output file cannot be edited; the data file can
be changed only by making changes to values In Screens ~ and/or 2. The output file and the
data file are ASCH files and can be edited using a text editor such as the Notebook editor found
In the Accessories group of W~ndowsTM.
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SCREEN 1 - DATA INPUT AND EDITING
The input data described in the following are required in Screen I, as displayed in
figure Aft. They can be changed by using standard W~ndowsTM editing techniques or by using
the spin or option buttons where provided. An example of an option button is the option for
the Section Type, as described ~ the following. Spin buttons are used for the design speed
and rainfall intensity on Screen 1.
The tangent section is the only section that accommodates different texture depths,
cross-sIopes, and pavement types within a single section. All other sections have only one
value for each of these variables in the PAVDRN model. Note that Screen ~ is Initiated with
default values that should be edited for the specific pavement section berg analyzed. Also,
Screen ~ is the only screen that coffins the menu bar at the top of the screen.
Section Description
This part of the screen allows the user to provide a description of the design sections.
Three lines, 72 characters each, are used to describe the section and any other unique aspects
of the simulation.
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Eric View Analysis Help
Data Input - Semen
~S=tion Description
Enter dest:'ipt've information
for this analysis here
[Use up to three lines to describe of label the analysis of this Motion}
~Sect'.n Type
0 Tangent
O Transition
O Vertical West
O Vertical Sag
~Rainfall Intensity,
~ Design S peed
@~
~Water Temperature ~Kmematic Viscosity-
~ @ ~
. _
~System of llnits~
BUS
O libretti': {SI}
n use data from upstream pavement section
_
Figure Apt. Example of PAVDRN input screen 1, environment and section type.
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Section Type
Five different design sections are considered (see figure A-2 for the plan and profile
views of each type of section).
Tangent Section. A tangent section is a straight section that may consist of up to ten
planes (sections with varying sloped that have unique cross-slopes, widths, texture depths,
and/or pavement types.
HonzontaZ Curve Section. A horizontal curve section contains a circular curve with
both the grade and superelevation specified.
Transition Section. A transition section is a straight section with a grade In which the
cross-sIope at the tangent end changes to meet the superelevation of the curved section.
Crest Vertical Curve Section. A vertical curve section is a section with a cross-slope
that crests between point of curvature (PC) and point of tangency (PT).
Sag Verucal Curve Section. A sag vertical curve section contair s a cross-slope that
sags between the PC and the PT.
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A
A MA
Plan Pmfi~e
al Tangent Simian
ALA
Or
1] MA
Plan Profile
Transition Se~ion
J
A /
I/? AM
Plan Profile
by HoNzonte' Cur Simon
A AM
-
Plan Profile
and c] Crest and Sag Verbal
Cu~s
Figure A-2. Pavement cross sections included In PAVDRN.
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System of Units
The system of units used for input and output (ST or English) may be chosen at the
option of the user.
RamfaU Intensity
The rainfall intensity must be selected by the user In units of in/in or mm/in. The
selection of a value for the rainfall Intensity is discussed In the following.
Water Temperature
The temperature of water flowing over the pavement surface must be selected by the
user In mats of °F or °C.
Kinematic Viscosity of Water
The kinematic viscosity used In this simulation is expressed ~ units of ft2/s, m2/s. The
value for the kinematic viscosity is calculated by an aIgori~chm within PAVDRN as a function
of the water temperature. The lowest possible water temperature should be used, keeping iIr
mind the ra~nfaD Utensil and the season of the year. The temperature of the water may be
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different than the ambient air temperature depending on pavement temperature and rainfall
duration.
Design Speed
The design speed for the pavement section being analyzed must be specified by the user
In either mi/h or km/in.
Multiple (Joined) Sections
If the simulation is set up for a pavement section that is downstream from a previously
analyzed section, and if the program output for the previously analyzed section indicates that
the flow path extended to the end of the section, click on the box. This option allows the
conditions existing at the end of ache previous section to be linked to the new section. A typical
screen for a Portland cement concrete pavement and a porous asphalt pavement are shown In
figures A-3 and Am.
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Data Input - Screen 2
Tangent Section
~Numbe' of Planes
_ _
1 ~
~Scct'an Lcngth
110110 ~
r pavement Grader
1-01 1
~Step S=e
~ Plane Properties
_
Plane 1
~Plane W;dth
112 1
Pavement Type
O DG^C ~ PCC
Q OGAC O G-PCt:
F[:'oss~ope
1 |.015 ~
rTcxhre Depth l
I Q2 1
Figure A-3. Example of PAVDRN input screen 2, geometric requirements for Portland
cement concrete pavement.
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Sag Vertical Curve
Length of Vertical Curve. Horizontal length of the vertical curve (ft,m).
Pavement Moth. Width of the pavement (all lanes sloping in one direction toward the
edge of the pavement) (ft. m).
Cross-siope. Cross-sIope of the pavement (ft/ft, m/m). The cross-slope value is
always positive.
Grade at PT. Longitudinal grade or slope at the point of tangency (PI) (ft/ft, mlm).
The grade value is negative if elevations decrease from left to right.
Grade at PC. Longitudinal grade or slope at the point of curvature (PC) (ft/ft, m/m).
The grade value is positive if elevations Increase from left to right.
Relive Elevation. Relative elevation of the PT to the PC (ft. m). The relative
elevation is negative if the Pr is lower than the PC.
Texture Depth. Mean texture depth using a standard sand patch test or equivalent fin,
mm).
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Step Size. Computational step size (ft. m). This value determines the points along the
flow path at which the water fihn thickness and hydroplaning speeds are computed. These
values are reported In the summary tables of ache output.
Pavement Type. Four types of pavements are used in PAVDRN; they are:
· PCC: Portland cement concrete,
· GPCC: Grooved Portland cement concrete,
· DGAC: Dense-graded asphaltic concrete, and
· OGAC: Open-graded or porous asphaltic concrete.
When grooved PCC is selected as the pavement type, text boxes for the groove spacing,
the groove width and the groove depth appear. This information is used to effectively Increase
the mean texture depth of the pavement.
If open-graded or porous asphaltic concrete is selected as the pavement type, an
additional text box is displayed to provide a place to enter a value for He permeability of the
pavement. This value is used to reduce the amount of water available for surface runoff. The
value for pavement permeability is set to zero for all other pavement types.
Direction of F70w to the Sag. This item requires that the user determine for which side
of Be sag vertical curve PAVDRN will calculate water film thickness and hydroplaT ing
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speeds. In some cases (i.e., where the PT or the PC is the sag point) only one selection is
meaningful.
PAVDRN RESULTS AS AN EXAMPLE
PAVDRN produces a summary report as the result of its execution. The report can be
viewed on-screen by selecting View or Analysis from the menu bar on Screen 1. The report
can also be printed and has two parts. The first part presents an "echo" print of the data
provided by the user. It should be examined to ensure that correct values were used In the
simulation of runoff over the pavement section. Table A-1 is an example of the data set
produced by PAVDRN for a tangent section. Table A-2 shows part ~ of fiche report produced
by PAVDRN.
TEST DATA SET - USERS GUIDE
Table Apt. PAVDRN input data set.
Tangent Section - 4 lane pavement with variable cross-slope
PCC Pavement
1,1,2,.00001134,55,0
2,1000,.01,3
24,.015,1,0,.02
24,.02,1,0,.02
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Table A-2. PAVDRN output - Part I: Echo print of input data.
PAVDRN - Highway Drainage Program - Version 1.O
developed by R. S. Huebuer (717)948-6127
Pennsylvania Transportation Institute
The Pennsylvania State University
University Park, PA 16802
Sponsored by the National Cooperative Highway Research Program
NCHRP Project 1-29
Program started on 5/ 1/1997 at 22:55:59
TEST DATA SET - USERS GUIDE
Tangent Section - 4 lone pavement with variable cross-slope
PCC Pavement
Type of section
System of units for input and output
Number of consecutive planes
Rainfall intensity (in/h, mm/in)
Kinematic viscosity (sq.ft./s, sq.m.is)
Section length (ft. m)
Longitudinal slope or grade (ft/ft, m/m)
Section design speed (mi/h, km/in)
Computational step size (ft. m)
Tangent
US
2
2.00
.llE-04
1000.00
.lOE-O1
55.
3.00
Plane No. Length Slope Pavement Infiltration Texture
(ft. m) (ftIft, m/m) Type Rate(in/h,mm/h) Depth (in, mm)
1 24.0 .015 PCC .000 .020
2 24.0 .020 PCC .000 .020
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The second part shows the results of the analysis In tabular form, table A-3.
Table A-3. Example of a PAVDRN analysis results screen.
Results for Plane No. 1
X Y Distance AFT Flow/width Manning's n Reynold's No. Hydr. Speed
(ft,m) (ft,m) (ft,m) (in,mm)(cfs/ft,cms/m)(mi/h,km/h)
.0.0.00- .20E-O1 . OOE+OO .000 0. 999999
2.03.03.61.21E-01 .17E-03 .092 15. 71
4.06.07.21.29E-01 .33E-03 .064 29. 65
6.09.010.82.35E-01 .50E-03 .051 44. 62
8.012.014.42.40E-01 .67E-03 .044 S9. 60
10.015.018.03.44E-01 .83E-03 .039 74. 59
12.018.021.63.47E-O1 . lOE-02 .035 88. 57
14.021.025.24.50E-01 .12E-02 .032 103. 57
16.024.028.84.53E-01 .13E-02 .030 118. 56
Notes: 1) + denotes Reynold's numbers greater than 1000.
(Manning's n may be in error)
2) * denotes hydroplaning speeds less then the facility design
speed of 55. (mi/h, km/in)
3) Hydroplaning speed is equal to 999999. for water
film thickness less than or equal to O.O
Time to equilibrium for place 1 is 2.19 min.
Total time to equilibrium at the end of this plane is
A-26
2.39 min.
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Table A-3. (Continued)
Results for Plane No. 2
X Y Distance WIT Flow/width Manning's n Reynold's No. Hydr. Speed
(ft,m) (ft,m) (ft,m) (in,mm)(cfs/ft,cms/m)
(mi/h,km/h)
16.0 24.0 28.84 .48E-01 .13E-02 .030 118. 57
17.5 27.0 32.20 . SOE-01 .15E-02 .029 131. ~ 6
19.0 30.0 35.55 .52E-01 .16E-02 .027 145. 56
20. ~33.0 38.91 .54E-01 .18E-02 .026 159. 55
22.0 36.0 42.26 .56E-01 .20E-02 .025 173. 55
23.5 39.0 45.61 .58E-01 .21E-02 .024 186. 55
25.0 42.0 48.97 .59E-01 .23E-02 .023 200. 54*
26.5 45.0 52.32 .61E-01 .24E-02 .022 214. 54*
28.0 48.0 55.68 .62E-01 .26E-02 .021 227. 53*
Notes: 1) + denotes Reynold's numbers greater than 1000.
(Manning's n may be in error)
2) * denotes hydroplaning speeds less than the facility design
speed of 55. (m'/h, km/in)
3) Hydroplaning speed is equal to 999999. for water
film thickness less than or equal to O.O
Time to equilibrium for plane 2 is 2.46 min.
Total time to equilibrium at the end of this plane is 4.65 min.
Program completed successfully at 22:55:59
The table contains X and Y coordinates for the flow path length, as well as the length
of the flow path. X and Y are zero at the beginning of the flow path. This location varies with
different pavement section types as described in the following section. The water film
thickness above the pavement roughness asperities and the flow-per-unit width of the plane
along the flow path are also displayed. The far right column shows the predicted hydroplaning
speed. (The basis for this value is described in the following). Manning's n and Reynold's
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number at each point are also presented. A number of notes that pertain to the results conclude
the output report. An estimate of the tune of concentration for the pavement section is also
reported. This value is useful in selecting an appropriate rainfall intensity for the analysis.
A comma~elimited, ASCH text file with the extensionplename.ASC contains Me data
shown ~ table Ant. These data can be incorporated into a ~ird-par~ plotting package to aid
In the interpretation of the results.
The origin of the flow Dath can be identified as follows:
Tangent Section
The origin can be located anywhere along the upper edge of the pavement section (i.e.,
the inside edge of the first plane).
Horizontal Curve Section
The origin is difficult to identify, however, the terminal point of the flow path is the
lowest point ~ the curve. Assnmmg a grade and superelevation, this would be at the corner of
the inside edge of the lower part of the curve. If the curve has no grade, the origin can be
located at any point along the upper or outside edge of the curve. The flow should be directly
across the pavement to the inside edge.
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Transition Section
If He tangent end of the transition and the curve end of the transition have slopes In the
same direction, the origin is located up from the end with the mildest slope and along the upper
edge of the pavement.
If the tangent end and the curve end of the transition section have adverse slopes, the
origin is located at the point of zero cross-slope along the length of the section. This point
should be accurately located by the x-coord~nate shown In ache printout. The flow path extends
from this point toward the end of the section with the mildest cross-sIope. This is not
necessarily the end with the smallest slope but, rather, the end where the change ~ cross-sIope
per unit per length is the smallest.
Crest Vertical Curve Section
The outlet of the flow path is located at the lower edge of the pavement section at the
PC or Pr, depending upon which side of the vertical curve is being analyzed. The origin is
located up-gradient from the outlet point. The x-coordinate of the origin is located using the
value shown in the printout. The flow path extends from this point toward the end of the
section with the mildest cross-sIope. It is not necessarily the end with the smallest slope but,
rather, the end where the change in cross-slope per unit length is the smallest.
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Crest Vertical Curve Section
The outlet of the flow path is located at He lower edge of the pavement section at the
PC or PI, depending upon which side of the vertical curve is being analyzed. The origin is
located up-gradient from the outlet point. The x-coordinate of the origin is located using the
value shown ~ the printout.
Sag Vertical Curve Section
The outlet of the flow path is located at the lower edge of the pavement section, i.e.,
the sag, where the longitudinal slope is zero. The origin is located up-gradient from this outlet
point. The x-coordinate of the origin is located using the value shown in the printout.
BASIS OF CALCllLATION
The basis for the value computed for the predicted hydroplaning speed is described in
detail in an article by Huebuer, Reed, and Henry (38). The algorithm uses two expressions for
computing the hydroplaning speed. The first is based on data collected by Agrawal and Henry
(44J and is based on a regression expression of their data (water film thickness versus
hydroplaning speed) to predict the hydroplaning speeds for water film thicknesses less than 2.4
mm (0.095 in). The second is used for water film thicknesses greater than 2.4 mm (0.095 in)
and is based on an expression developed by Gallaway et al. (4), where the hydroplaning speed
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is a function of water film thickness, tire tread depth, pavement mean texture depth, and tire
pressure. Conservative values of the tire pressure, 165 kPa (24 lb/in2), and tire tread depth,
2.4 mm (3/32 Ins, were used in the PAVDRN model to generalize Gallaway's expression.
One method for the selecting the design rainfall intensity for the hydroplaning analysis
is based on the frequency and duration of an event. It is recommended that a frequency of 100
years (100-year return period) be used representing a one-percent risk or chance, so the
Intensity will be exceeded. The duration should be based upon the pavement's time of
concentration. The time of concentration can be determined using output from the PAVDRN
model. In summary, the key parameters for selecting a value of rainfall intensity based on
hydrologic considerations in order to estimate the hydroplariing potential of a pavement surface
are: (1) location, (2) risk level, and (3) time of concentration.
A second method of selecting a rainfall intensity for hydroplaning analysis is by
examining the effect of driver response. Table AN was developed based upon work done by
Hayers et al. (45) and AASHTO.
Clearly, the selection of the design rainfall intensity for analyzing He hydroplaning
potential of a highway section needs to consider both driver response and the likelihood of an
event or risk. It is recommended that the designer employ a value from table AN to establish a
maximum rainfall intensity specifically for determining the potential for hydroplaning on the
designed pavement section. The value should be compared with the rainfall information 0-D-F
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curves) for the location of the project. The user should select the lesser of the two values and
use it for completing the hydroplaning analysis of the pavement section.
Table A4. Rainfall intensity for stopping sight distances.
Design Speed Stopping Sight Maximum Rainfall Intensity,
m/in, (kmlh) Distance, It (m) in/in, (mm/h)
.
50 (80)
55 (88)
60 (96)
65 (104)
70 (112)
475 (145)
550 (167)
650 (198)
725 (221)
850 (259)
5.96 (151)
4.18 (186)
2.88 (73)
2.18 (55)
1.54 (39)
A-32
Representative terms from entire chapter:
flow path
